Vispect is a simple program for preliminary estimation of SO2 column amounts recorded by miniature dispersive UV spectrometers, which are mainly produced by Ocean Optics. It uses the ratio between the pixel values within and outside the SO2 absorption band as a proxy for the column amount of SO2. These are linearly related at low gas concentrations.
Vispect allows someone with only a few minutes' training to record accurate spectra in the field.
[link to paper when it's available]
[link to DOASIS scripts when available]